io.netty.handler.codec

类 MessageToMessageDecoder<I>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.MessageToMessageDecoder<I>

所有已实现的接口:

ChannelHandler, ChannelInboundHandler

直接已知子类:

Base64Decoder, ByteArrayDecoder, DatagramDnsQueryDecoder, DatagramDnsResponseDecoder, DatagramPacketDecoder, HttpContentDecoder, MessageAggregator, ProtobufDecoder, ProtobufDecoderNano, RedisArrayAggregator, SctpInboundByteStreamHandler, SctpMessageCompletionHandler, SctpMessageToMessageDecoder, SpdyHttpDecoder, StringDecoder, WebSocketClientProtocolHandler, WebSocketExtensionDecoder, WebSocketServerProtocolHandler

public abstract class MessageToMessageDecoder<I>
extends ChannelInboundHandlerAdapter

ChannelInboundHandlerAdapter which decodes from one message to an other message. For example here is an implementation which decodes a String to an Integer which represent the length of the String.

     public class StringToIntegerDecoder extends
             MessageToMessageDecoder<String> {

          @Override
         public void decode(ChannelHandlerContext ctx, String message,
                            List<Object> out) throws Exception {
             out.add(message.length());
         }
     }
 

Be aware that you need to call ReferenceCounted.retain() on messages that are just passed through if they are of type ReferenceCounted. This is needed as the MessageToMessageDecoder will call ReferenceCounted.release() on decoded messages.

嵌套类概要

从接口继承的嵌套类/接口 io.netty.channel.ChannelHandler

ChannelHandler.Sharable

构造器概要

构造器

限定符	构造器和说明
protected	MessageToMessageDecoder() Create a new instance which will try to detect the types to match out of the type parameter of the class.
protected	MessageToMessageDecoder(java.lang.Class<? extends I> inboundMessageType) Create a new instance

方法概要

限定符和类型	方法和说明
boolean	acceptInboundMessage(java.lang.Object msg) Returns true if the given message should be handled.
void	channelRead(ChannelHandlerContext ctx, java.lang.Object msg) Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected abstract void	decode(ChannelHandlerContext ctx, I msg, java.util.List<java.lang.Object> out) Decode from one message to an other.

从类继承的方法 io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

从类继承的方法 io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

构造器详细资料

MessageToMessageDecoder

protected MessageToMessageDecoder()

Create a new instance which will try to detect the types to match out of the type parameter of the class.

MessageToMessageDecoder

protected MessageToMessageDecoder(java.lang.Class<? extends I> inboundMessageType)

Create a new instance

参数:

inboundMessageType - The type of messages to match and so decode

方法详细资料

acceptInboundMessage

public boolean acceptInboundMessage(java.lang.Object msg)
                             throws java.lang.Exception

Returns true if the given message should be handled. If false it will be passed to the next ChannelInboundHandler in the ChannelPipeline.

抛出:

java.lang.Exception

channelRead

public void channelRead(ChannelHandlerContext ctx,
                        java.lang.Object msg)
                 throws java.lang.Exception

从类复制的说明: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

channelRead 在接口中 ChannelInboundHandler

覆盖:

channelRead 在类中 ChannelInboundHandlerAdapter

抛出:

java.lang.Exception

decode

protected abstract void decode(ChannelHandlerContext ctx,
                               I msg,
                               java.util.List<java.lang.Object> out)
                        throws java.lang.Exception

Decode from one message to an other. This method will be called for each written message that can be handled by this decoder.

参数:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

msg - the message to decode to an other one

out - the List to which decoded messages should be added

抛出:

java.lang.Exception - is thrown if an error occurs